Propeller.



I. W. WALTERS.

PROPBLLBR. n APPLICATION FILED APR. 19, 19,10.

1,087,203. Patent-ea m5111914.

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JULIUS WM. WALTERS, 0F GLENS FALLS, NEW YORK.

rRoPELLEr..

Specification of Letters Patent. Patented -Feb. 17, 1914.

appumionmea April 19, 1910. serial Nofsseso.

To all lwhom 'it may ooncem:

Be it known thatgI, J ULIUS W WAL'rERs, a citizen of the United States,residing at Glens Falls, in the county of Warren and State of New`York,'have invented new and useful Improvements in Propellers, ofwhiehthe following is a specification.

My invention relates to propellers ofthe radial blade type.While'having-the particular relation specified, there are a number offeatures involved, which may be used with great ensuing advantage inconnection with propellers of other types. 0n the other hand there arecertain features which are of'particlar value when used in connectionwith propellers of the radial blade type, and it wil be noted upon anunderstanding of my invention that vthe entire number of featurescoperate with each other when combined together in the embodiment whichI-'s'hall disclose to produce a propeller givingthe most eiiicientresults.

In a great number of propellers in use at Ythe pr`esent'timeconsiderable diiiculty is eX- perienced inimaking them efficient owingto each of several causes. By many propellers up ofthe watersboth" there.is a next tothe hub, and away from 1t, wththe result that the water isnot in condition for a most eicient vpurchase to be had by the propellerupon it. 'Frequently this breakingl up of water occursnext the cuttingedges of the propeller, with the result that the Aportions -o'f theblades in the rear of the :cutting edge are forced -to act ineliciently.The resulting slippage or so-called sli Vof the propeller is renderedgreater by t is action of the propeller, andthe speed of the Vessel befing driven is correspondingly decreased. -InA connection with manyvpropellers also there is considerable centrifugal action of th`e pro-1peller on the waters next thehub, and the j water soacted upon is thrownout in such a1 manner as to project vit beyond the range ofi action ofthe outer portions -of the blades.z The slip of the propeller is alsoincreased 'l due to this action. And in all of these in stances thebreaking up of the water and the resulting irre lar action of 'thepropellerv4 upon it, especially at high speeds, results in a vibrationof the propeller and shaft which is transmitted to the machinery andthe; frameof the vessel, becoming inmany instances vcry objectionable onaccount of the jarring of the machinery, and the unpleasant vibration ofthe walls of the vessel,

Many attempts have been made to over- 4the spiral form of screwpropellerhas been used, and the multi-blade spiral, the vblades of which emanatefrom the huband follow a spiral of gradually increasing diameter, butnone of them so far as I am aware, have been a successful solution ofthe problem in all of its phases. These diiiiculties may have beenremoved in a propeller'designed for a certain speed,- but at certainother speeds, the same propeller has been found inefficient, and apropeller of the same design'could not be made to work efficiently. Soalso in some propellers one dilficulty has :been sought to be remedied,Iand in some zanother.

It is the object of my invention likewise, xto overcome the diiiicultiesnamed, and I 'have so far succeeded that the propeller of .my inventionoperates at a greatly increased eliciency, and a propeller of the samedesign may beused over a wide-range of speeds with'the same eliicientaction, breakin up of the water, and centrifugal action yo the.propeller on it, and the resulting slip having lbeen reduced to aminimum.

In the accomplishment of the object' lof ;my invention I use amulti-blade propeller. I -so shape .and associate the blade withthe Ihuband so form them and their driving Aedges and faces that all of theabove-named difficulties are overcome in greatmeasure.

My invention will be readily yunderstood and appreciated from aconsideration of the accompanying dr'awingsin connection nnanner ofassociation and formation of the lblades of the propeller of myinvention are the blades. The driving faces Aof the blades are formedcommencing tangent to the hub .105 10 is the-hub of the propeller and 11are as at 12. At this poi-nt the elements of the driving facesaresubstantially perpendicular toa transverse plane, represented by line13, 13. Iextend the blades outwardly and rearwardly along a conicalspiral curve,

until they reach a certain maximum diameter 14 at a point 15 in theirlength. From this point on I extend them along a helical curve at adiametery equal to the maximum diameter 14. I terminate the vbladesbefore there is apparent overlapping in end projection of the propeller,the blades being terminated before they occupy an angle of 180 aroundthe axis of the hub.

After leaving the hub the face ofthe blade instead of continuingperpendicular to a transverse lane 13,l 13, is increasingly inclined toit, t e rear edge of the blades being lagged behind the cuttin edge,until .a point at or near the point o greatest diameter is reached.Thereafter the incline of the blades to a transverse plane is maintainedsubstantiall uniform. The blades also are formedfof7 increasing widthfrom the hub outwardly, and are glven the crosssections shown in Figs.3, 4, and 5, It will be observed that the blades are thickest at a pointnearer the rear edge of the blade than thev front edge, or over half-wayof the width of face of the bladev in anyinstance from the cutting edgeto the rear edge. The sectional areas are substantially triangular inshape. Y

By virtue of the commencing of the disturbance ofthe water at the hub,the propeller in effect worming its way through the water in muchvthesame manneras does a worm propeller. Gradually the wateris acted upon bythe faces of the blades which follow the spiral curve of increasingdiameter rearwardly, until it is movin as a substantially solid column,in whic shape it is ready to be acted` upon and is acted upon by theouter portions of the blades, which are formed on the rearwardlyextending spiral curve of substantially Y uniform diameter. Breaking upof the water due to f rotation ofthe blades adjacent the hub, and' dueto `centrifugal' force is reduced to a minimum, and the solid body ofWater ualwaysin the region of the propeller is constantly acted upon vbynew portions of the blades.

hi h. v

nd that by simply increasing the incline of the blades rearwardly or inother words by simply decreasing the conical angle of the spiral curveon which the blades are formed V 6o with respect t the axis of the hub,l mayreadily adapt the propeller of my inventionto use at higher'speeds.This is illustratedl by the dotted lines in Fig. 1, the points at whichthe blades reach their maximum diameter of revolution for speeds of'600,` 800,

blades, tangent to the hubs, there is little- Slip is therefore low andefficiency;

noemer 1000, 1200, and 1400 revolutions being indicatedl separately. Itwill be notedthat as the speed is increased, the conical angle of thecone of the spiral of the rearwardly extending blades is decreased.Preferably the maximum diameter of revolution 'of the blades ismaintained substantially uniform in the designs for a wide range ofspeeds. lt is assumed of course the blades are elongated in order thatthe maximum diameter may be ,preserved when the conical angle isdecreased. The propeller Lof my invention is thus made suitable for useat various speeds throughout a very wide range.

Despite its peculiar shape the propeller is so constructed that it willwithstand all the strains imposed upon it under the most severeconditions of normal use without breaking, and this without impairingthe efficient cutting action of the blade in the water. nearest the hubo n the rear edges of the blades, this thickened portion acting as abackbone as it were, and thus giving strength where strengthr` is mostneeded. By virtue of this provision also the blade is made to tapergradually from the cutting edge rear- The blades are thickest at pointswardly substantially to the rear edge,

the action of the blades upon the water is made knife like, thesolidarity vof the water acted upon by the propeller being thus furtherpreserved. f, Owing to the fact that each blade occupies an angle less'than 180 around the axis of the hub, they may very.

readily be made of such cross-section aste be quite rigid. It is owingto the ecient action of the propellerl'lpon the water in'the 'peculiarmanner previous'y described, that the linear length of ,the b ades isreduced, and it is by virtue of this lreduction to such extent that theyAoccupy angles less than 180, without apparent overlapping in endprojectionthat the action of the blades upon the water is madesubstantially independent, resulting in further increase in eciency.

Whatlclainlis: A propeller comprising a hub and blades 'extendingoutwardly and rearwardly 'om the hub along a 'conical spiral curvethrough 'approximately 180 degreesto. a predetermined maximum diameterand thence along a helical c lindrical curve of said maximum.

diameter ess' than 45 degrees whereb to prevent overlapping in endprojection o the blades, said blades increasing 1n width 'om the hub totheipoint of mam'mum diameter thence decrea ends, the working faces ofthe blades commencing tangent to the hub'whereb to admit of free radialflow of the fluid om-the huband odset vortexing, said working facescontinuing outwardly andbackwardly at an increasing inclination to thetransverse plane of the hub, the rear edges of the blades `inwidth17o-their ends 'and decreasing 1n thickness toward their lagging beh-indthe cutting edges up to the` ln testimony whereof I have hereunto setpomt of maximum diameter and thence bemy hand in presence of twosubscribing wit- 10 ing uniformly inclined Whe-reb the 'pronesses. npeller is given worm action e ectingy the movement of the Huid in alsubstantially JULIUS WM WALTERS solid column, the outer cylindricalportions Witnesses:

of said blades acting upon the solid column A. C. VANDERZEE,

of the fluid. v .TosmPH KOBER.

